1. Field of the Invention
The present invention relates to a droplet information measuring method and a apparatus therefor, a film pattern forming method, a device manufacturing method, a droplet discharge apparatus, an electro-optical apparatus, and an electronic apparatus.
Priority is claimed on Japanese Patent Application Nos. 2003-195826, filed Jul. 11, 2003, 2003-195827, filed Jul. 11, 2003, and 2003-195829 filed Jul. 11, 2003, the contents of which are incorporated herein by reference.
2. Description of Related Art
The manufacturing process for an electronic apparatus such as an electro-optical apparatus or a semiconductor device or the like which is used as a display or a display light source or the like, includes steps of depositing a material upon a substrate, and forming a film upon this substrate. The technique for depositing material and the technique for forming a film are intimately related to the quality of the products and to their function, and are very important in the struggle for the enhancement of the performance of the above described apparatuses.
As a technique for depositing material upon a substrate, for example, as disclosed in Japanese Unexamined Patent Application, First Publication No. H11-274671, there is a method of discharging a liquid material as droplets via a nozzle which is provided to a discharge head. With this droplet discharge method, as compared to a technique such as a spin coating method or the like, there are the beneficial aspects that the waste in the consumption of the liquid material is small, and that it is easy to perform control of the amount and the position of the liquid material which is deposited upon the substrate.
In techniques for forming a film upon a substrate using a droplet discharge method, in many cases, a plurality of droplets are deposited upon the substrate in series. In such a case, it may happen that the drying conditions of a droplet may vary due to the influence of the vapor which escapes from another droplet, and this may lead to deterioration of the quality of the resultant layer.
In addition, with a droplet discharge method, it is easy for the conditions of discharge, such as the amount of discharge of the droplets from the discharge head, to vary according to the characteristics of the liquid material. Due to this, it is desirable to determine the drive conditions of the discharge head appropriately in correspondence to the liquid material which is used, such as for example the lot modification time of the liquid material and the like.
Optimization of the drive conditions, for example, may be performed by depositing a pattern of the liquid material upon the substrate, and by checking the state of this deposit. That is to say, it is performed by repeating trials of the above described pattern deposition, while varying the drive conditions of the discharge head, until the state of pattern deposition is as desired. However, this method invites a deterioration of productivity, since it requires a long time period.
In addition, for efficiently planning the optimization of the drive conditions, it is desirable directly to measure droplet information such as the mass of a droplet which has been discharged from the discharge head, and to manage the drive conditions based upon the results of this measurement. However, since the droplets which are discharged from the discharge head are very minute, a great deal of time is required for this measurement, or obtaining a stabilized measurement result may be difficult.
For example, if the amount of a droplet (its mass or its weight) is to be measured, there is a method of measuring the weight of a single droplet by measuring the weight of a large number of droplets (for example, of 5000 drops) all together, and by dividing the result of this measurement by the number of droplets; but, in this method, a lot of time and of material are required for discharging the droplets for the measurement. On the other hand, if an attempt is made directly to measure the mass of a single drop of liquid by using an accurate measuring apparatus, errors can easily arise due to the influence of the viscoelasticity of the droplet.
The present invention has been conceived in consideration of the above described circumstances, and it takes as its object to propose a method and a apparatus for measuring droplet information which can be desirably used when depositing a plurality of droplets in sequence, and in addition a droplet information apparatus which can measure information for the droplets which are discharged from a discharge head in a stable manner.
In addition, another object of the present invention is to propose a film pattern forming method, which is capable of striving for the enhancement of film quality.
In addition, another object of the present invention is to propose a device manufacturing method, an electro-optical apparatus, and an electronic apparatus, which are capable of enhancing product quality.